Ingot mold



Patented Feb. 21, 1928.

UNITED STATES EMIL GATHMANN, OF BALTIMORE, MARYLAND.

INGOT MOLD.

Application filed July 22, 1927. Serial No. 207,725.

This invention relates to ingot molds'of thekind which are open at topand bottom. Such molds are provided with a plug adapted to close the bottom opening of the mold and are usually fitted with a shrink head pas eaing at the upper part, 'but this latter ture is not a part of this invention. My invention is particularly intended for use 1n molds of the kind commonly known as Gathmann big-end-up molds, in which the mold is top poured and is provided with a tapered opening in its bottom adapted to receive a plug, by means of which the mold 1s closed and the ingot may be disengaged or loosened from contact with the mold walls and stripped from the .mold by suitable tongs without reversing or upending the mold.

In my U. S. Patent No. 1,419,454 of June 13, 1922, and in other patents granted to me I have shown molds of this kind, 1n which the stripping plug is associated with a sealing plate or similar device, which plate serves to moreor less effectively seal the bottom opening of the mold and protect the plug from the direct impact of the molten metal being poured into the mold to form the ingot. This device, while fairly satisfactory, is quite expensive as the plate adbe used only once and the plug, thru leakage of the metal underneath the plate, is

frequently welded to the ingot, usually making it unfit for further use. I have found that the bottom opening of the mold may be more completely sealed and the stripping plug better protected by a novel arrangement of two superimposed plugs, which are given contours best adapted for sealing and stripping purposes.

According to. "my present invention, a stripping plug is seated in the bottom opening of the mold in the usual way and a sealing lug, which is relatively short as compare with the stripping plug, is seated in the lower portion of the mold a short distance above the top of the stripping plug but so as to be out of contact therewith.

In this way the stripping plug may be so to seated as to close the bottom opening and reject below the bottom of the mold so that it may be utilized as a pusher or stripper if the ingot sticks to the mold. Thesealing plu is adapted to; be forced to its seat until 1ts periphery makes a contact with the heres to the ingot in stripping and thus can walls of the upper portion of the mold bottom opening so that none of the liquid steel may pass to contact with the stripping plug. The walls of the bottom opening are preferably tapered and the periphery of the plugs is correspondingly tapered. In this way a good fit is obtained with small chance of leakage of any of the molten metal forming the ingot.

The stripping plug is preferably made of cast or forged metal and may be used many times. As it is not possible always to.obtain a smooth, uniformly-tapered peripheral surface on the stripping plug due to its length and also because of the abrasions which it receives in use, I employ the second plug which is relatively short and has a limited peripheral contacting surface,

which may be more accurately formed and seated. This second plug, which I call a sealing plug, is preferably made of refractory material, such as fire clay, capable of resisting the high temperature of liquid steel without spawling or cracking. It is withdrawn from the mold with the ingot to which it adheres and is intended to be used only once. This sealing plug preferably has a tapered periphery which fits closely in the tapered seat of the bottom opening of the mold in which it may be depressed until leak-proof contact is made with its seat. By this wedging effect of the taper the plug cannot float upwardly or move from its position during the pouring of the ingot, and

the arrangement is such that this plug never comes in contact with the stripping plug; otherwise its movement might be so arrested as'to' prevent proper seating.

My improvements are illustrated in the accompanying drawings in which:

Figure 1 shows a vertical central section of a big-end-up mold of the Gathmann type embodying my present invention. 1

Figure 2 is a detailview in vertical section and on an enlarged scale of the lower portion of the mold and the mold stool shown in Figure 1.

Figure 3 is a View similar to Figure 2 of a modification.

The mold Ais formed with a bottom opening a which is tapered downwardly and receives the stripping plug D. The mold rests on a stool B having an opening I; into which the plug D extends. Preferably as shown in Figures 1 and 2, the mold cavity is necked-in with conc ave and convex walls or, 3 of the kind heretofore employed and this necked-in portion merges into a lower mold portion a which connects with the bottom opening a.'

The plug 0 is preferably made of refractory material and fits into the lower mold portion a. It will be observed by reference to Figure 2 that the plug .0 is relatively short as compared with the plug D. Its upper peripheral portion is tapered and is adapted to fit closely the adjacent tapered walls of the mold. The lower portion a of the plug is preferably'more decidedly tar pered so that it cannot come in contact with the mold walls;

When the stripping plug is fully inserted,

i its upper end is usually a short distance below the top of the bottom opening a although, owing to irregularities in casting,

it may sometimes project slightly above this opening. The upper peripheral'surface of the plug C is relatively thin, the lower tapered surface a being employed mainly for strengthening purposes, and will fit more accurately in its seat than the longer or' stripping plug. The Walls a are, as before stated, tapered and the taper of the upper part of the plug conforms to the taper of these walls; The dimensions are such that the sealing plug can never be lowered to the bottom of the walls a so that when the plug is fully inserted, there is a clear space 8 between the plug C and the plug D. In this way the mold may be completely sealed and the stripping plug properly protected.

In Figure 3-1 have illustrated a slight modification. Most of the parts are similar 'to those shown inFigures 1 and 2 and are similarly lettered. In this instance is shown how the two plugs are utilized in a mold the bottom opening of which has a continuous or uninterrupted taper.

'I claim as my invention:-

1. An ingot mold open at top and bottom provided with a bottom closure consisting of superimposed plugs, the bottom face of the upper plug being out of contact with the ing beyond the bottom of the mold, and a tapered sealing plug seated in the lower 'portion of the mold a short distance above the stripping plug.

4. An ingot mold having a bottom open- .ing with tapered walls, a tapered stripping plug seated in said bottom-opening and a relatively short tapered sealing plug seated in the lower portion of the mold a short distance above the stripping plug.

5. An ingot mold having a bottom opening, a strippingplug seated in said bottom opening and a relatively short sealing plug seated in the lower portion of the mold a short distance above the top of the strippingplug and which has a tapered periphery fitting the mold walls and a relatively narrow lower portion which is out of contact with the mold walls and out of contact with the top of the stripping plug.

6. An ingot mold having a bottom opening with tapered walls, a tapered metallic stripping plug seated in said bottom openings and another relatlvely short tapered plug of refractory material seated in the lower portion ofthe mold a short distance above the top of the stripping plug and which serves to seal the bottom opening and to protect the stripping plug from the impact of the molten metal poured into'the mold.

In testimony whereof, I have hereunto subscribed my name.

EMIL GATHMAN N 

